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Been doing a bit of light load/ highway tuning of my 260RS. Leaned it out a fair bit. Last tank was 12L/100km (half highway, half around town). I'm a bit disappointed to be honest. I reckon it can do better...

thats pretty bloody good!

i have put mine back to stock ECU, stock boost - and curious to see how it behaves. did new plugs and cleaned AFM meter last week, and trying to keep it off boost as much as i can.

a point of interest is my recent dyno tuning showed the stock fuel map really loads fuel in between 2500 and 2500rpm, which is commonly where i shift - so try short shifting it to keep it out of that area (for RS4S owners).

what annoys me though is the way the fuel gauge barely moves for the first 100km's of the tank, then drops rapidly - to 3/4 - then it takes about 350km to get to half - and then the last half a tank just EVAPORATES over the next 100km's! it's quite deceiving! just when you think you're doing ok out of this tank, BOOM, it laughs in your face!

thats pretty bloody good!

i have put mine back to stock ECU, stock boost - and curious to see how it behaves. did new plugs and cleaned AFM meter last week, and trying to keep it off boost as much as i can.

a point of interest is my recent dyno tuning showed the stock fuel map really loads fuel in between 2500 and 2500rpm, which is commonly where i shift - so try short shifting it to keep it out of that area (for RS4S owners).

what annoys me though is the way the fuel gauge barely moves for the first 100km's of the tank, then drops rapidly - to 3/4 - then it takes about 350km to get to half - and then the last half a tank just EVAPORATES over the next 100km's! it's quite deceiving! just when you think you're doing ok out of this tank, BOOM, it laughs in your face!

thats usually a problem with the fuel "leveler" thingy in the tank.. another one of the guys told me that when i run ethanol it should actually fix this issue(mine was doing it to) so as im on e85, it seems to have cleaned the contact part on the leveler... now mine doesnt play tricks any more.. lol

After driving to a rally on the weekend, I topped up the tank so I'm now running about half BP Ultimate, and about half United 98 Premium (which was giving rubbish economy). Driven like a granny 90% of the time, so far 8.3km/L, looks to be 600+ km per tank. Amazing what staying off boost can do for economy!

Just for comparison my temporary vehicle, a 1994 Toyota Camry 3L V6 is doing 11.4 L per 100km around town (and of course it doesn't have a turbo). I was getting 12 - 15L per 100 from my C34 and have been warned it will get worse with the RB30!

  • 3 months later...

Just managed to see a big improvement in fuel economy with the install of the shift kit.

New best is a 9.3L/100km from Goulburn to West Ryde. This was sitting on an average 116km/h on the freeway.

Also got 10.3L/100km on a Canberra - Jindabyne (2 trips to Perisher) - Goulburn trip.

Very happy with this.

Just managed to see a big improvement in fuel economy with the install of the shift kit.

New best is a 9.3L/100km from Goulburn to West Ryde. This was sitting on an average 116km/h on the freeway.

Also got 10.3L/100km on a Canberra - Jindabyne (2 trips to Perisher) - Goulburn trip.

Very happy with this.

Well that's a surprising benefit!

  • 4 weeks later...

Hey All

One of my first posts since I took delivery of my C34 RS4S. Its a great car and goes surprisingly well. Its such a sleeper, its great! :)

Thought it would be interesting to post my first two fuel consumption figures as my car is absolutely stock standard. Not a single mod except a turbo timer.

Both figures are mixed hiway and city driving plus its a new car for me so I have been giving it a good squirt in between.

First 58L Caltex 98 to 498kms = 11.6 L/100km

Second 55L Caltex 98 to 510 = 10.8L/100km

I imagine if I was going easy and not getting on boost much it would drop to 9L/100 easy.

I'm pretty happy with that as just about any car of a similar size (commodore wagon, camry, liberty) will use the same or more. Only difference is when the RB lights up all the others will be in the rear view mirror! :)

Cheers!

just got 12.5ish from my last tank+$50 worth (about 720kms from $130 fuel) and thats running 95ron and semi highway (actually delivering pizzas lol, lots of 60kms cruising and minimal stopping till you get near ppls houses)

i think im going to get a wideband and a simple piggy back so i can lean out my cruise and light load a bit more (seeing as im pretty stock)

if only i could justify a nistune at the moment :/

I filled my tank and got about 220ks out of it before the fuel light came on...

I wonder if that could be related to my plugs fouling so badly the car literally would not start?

Me thinks that's not necessarily a good indication of a Stag's fuel consumption :)

I filled my tank and got about 220ks out of it before the fuel light came on...

I wonder if that could be related to my plugs fouling so badly the car literally would not start?

Me thinks that's not necessarily a good indication of a Stag's fuel consumption :)

definitely something wrong, check for boost leaks and go from there

o2 sensor will cause bad fuel consumption but not that bad

could also be leaking injectors or even bigger injectors (jap fitted) that just run with the stock ecu (but i doubt this)

One of my first posts since I took delivery of my C34 RS4S. Its a great car and goes surprisingly well. Its such a sleeper, its great! :)

Thought it would be interesting to post my first two fuel consumption figures as my car is absolutely stock standard. Not a single mod except a turbo timer.

Both figures are mixed hiway and city driving plus its a new car for me so I have been giving it a good squirt in between.

First 58L Caltex 98 to 498kms = 11.6 L/100km

Second 55L Caltex 98 to 510 = 10.8L/100km

I have averaged somewhere between those two in my rs4s for the last 4 tanks.

Keep boost guage in the neg, driving these things slow is freaking hard though....

Wow, nice effort Dasic1.

Compared economy before and after my tune.

11.1km/L getting there on the freeway/highway and 12.4km/L getting home.

All up 260kms travel + nearly 4 hours on the dyno and used just over 1/3 of a tank.

Just filled up my second tank of BP 98 in my 'new' C34 s2 RS4V, 11.6L / 100km.

Pretty happy with that, mostly freeway driving but with some acceleration and start stop.

Fuel consumption was the last thing that I was anxious about, but it seems to be not much worse than my HR31 (10.9-11.3 on my typical commute).

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